OFF TOPIC.
Reminds me of one flight I had during my CF-101 Voodoo experience (2,000 hrs). I was wing man and while in IMC, lead called me into line-astern position for maneuvers. After a few minutes I remarked to my backseater that - gosh, did I ever have the leans - and I could swear that we are inverted right now. He responded: "Yep we are - this is the last half of three rolls" !
Back ON TOPIC

Hello Bearfoil;

Understand what you mean but there is no indication in the BEA Update that the aircraft was not in stable flight, likely level, not climbing or descending. The QRH drill and checklist are clear. The meaning of "stability" in this context has to do with steady-state power settings and a level pitch attitude as required by the QRH checklist. Certainly there are going to be pitch variations around a "nodal point" in turbulence but the power isn't going to change once the AT is disconnected.

An autopilot disconnecting in cruise is not a big deal but one certainly, immediately, looks for the cause. I recall from discussion with people who knew the airplane well (when learning the airplane in 1999) that the EFCS is "way ahead" of all systems - and responds much faster than the pilot can to changes or system problems. That it took ten seconds or so between the AP disconnect and the annunciation of the pitot problem may be due to the extensive BITE test processes which ensure the accuracy of the fault, (correlation) and both communication (SDAC > FIDS > FWC1 > FWC2 > CMC, CMS & DMCs). Lack of correlation will cause a WRG fault to be included in the fault message. During that time we do not know what either crew member saw on his PFD in terms of failing AS. We cannot know what the #2 PFD displayed but I have argued elsewhere that it was about the same as the other two; no pilot would try to control high speed with such a pitch-up. The power would be brought back first, then possibly speedbrakes used. We will know soon enough.

Regardless, a loss of airspeed information is no time for swift action, especially in weather. It is time for deliberate, measured action that is slowed down and closely coordinated with the PNF, (announcement by the PF of the drill or checklist, PNF's participation in the checklist or memory item and/or concurrence if a change in flight path/direction is indicated, completion of the challenge-response checklist, securing the aircraft after the abnormal is over, communicating with ATC, Company, F/As).

It is no time for individual action which leaves the other crew member unaware of the course of action and therefore unable to assist. We do not know what occurred during this period except that which the BEA Update includes. Again, we will know soon enough.

The failure to log onto DAKAR still bothers me. In itself it is no big deal providing communications are established on HF (which they were) but they needed a clearance to deviate off-course and didn't get it. CPDLC makes such clearances easily and quickly obtainable. It didn't seem to be an emergency diversion around a build-up they didn't see. Anyway...another item for the BEA to think about.

Partner transparency or opacity?
 

bearfoil Question: During their ordeal the System presented a transparent (an clear) picture to the poor guys? :confused: They were informed why the plane "degraded". They were reliably informed they were stalling? The stall warning worked as expected by a crew badly needing reliable information? IMHO this is "little bit" closer to "partner opacity". :}

The "persistent NU..." (from BEA) is coherent with "transparency" from the partner to the PF? :confused:

It has occurred to me, that when comparing the flyability, ergonomics, shock resistance & recovery ability of the Airbus FBW cockpit and control systems, as a flight control centre, it should be borne in mind that effectively what Airbus did in a decade or so was:

re-invent the cockpit form a pilot's perpective. Throttle levers that don't feedback, sidestick control, glass display including 'digital' and 'text' (albeit some strip) instruments replacing mostly analogue, etc.

A pretty monumental paradigm shift - but did everyone truly admit that this is what it represented, rather than perhaps Airbus & others leading the industry to describe (even excuse) it somewhat as 'not really different in principal'.

It is in fact very different, all-round, and in principal to what three-quarters of a century of flight up to that point had evolved as a modern cockpit...

It has been 'bedding down' ever since, into the aviation world's sub-conscious. Additional settling in is still taking place... the investigation of this accident, as so many before with more conventional cockpits had done, will be another step to fully accepting some of the imperfections that this man-machine interface represents and correcting them.

Only by being very open about the crew's cockpit experience, and their response - what was expected and what came naturally, can we further improve the modern 'cockpit flight centre' by integrating the best of both worlds.

Like the last UK Govts attempt at a 'truly joined-up government policy', the dots might all be there, but most are still quite some way from being even crudely connected, let alone integrated as a comprehensible, efficient and finely optimised cockpit for flight control.

It seems inevitable that mistakes were made in many areas of design as well as pilotage; even at this early stage it worries me that justifying them (individually) is quite possible, but never as a joined up whole for safely governing an aeroplane's flight under extreme and singular conditions.

Hi,

Why always repost this speculation ?
By myself I read (and it's not a speculation .. but a fact!) the aircraft was stable because he was in a cruise flight stabilized by the autopilot and auto throttle
When autopilot and auto throttle go out of the loop .. we don't know if the airplane stay "stable"
So maybe .. instead of touch nothing (hands off) the pilot had to act immediately for stabilize the plane
Remind .. the plane immediately banked to right (unfortunately no clue about the bank angle from BEA note ....)
So will the pilot wait the aircraft go in a 30° or more bank angle before react ?

Hi PJ2

Thanks for such a quick reply. I am happy to see you acknowledge that BITE may have forestalled a cockpit annunciation of the problem. Would this not mean that the PF directly after a/p loss would be flying with the assumption of NORMAL LAW? Otherwise you are condemning this man to a blunder: to wit, not being patient with the a/c post auto? At the least it establishes that there may have been confusion re: LAW.

As I have said, if the PF was performing as you state he should, then some control inputs would be most normal in NORMAL? His acknowledgment of "So, lost speeds", is an admission in fact that ALTERNATE LAW is a new development for the crew, occurring as it did eleven seconds after a/p loss. This is a very long time to be unaware in a task laden cockpit, with MASTER CAUTION, and a STALL STALL in the interim twixt a/p drop and observation of "Lost Speeds", No?

The Note states that the a/c passed through ten degrees NU and increasing "Before it started to climb", why so long if the a/c attitude was stable at 'Level'? Was this a/c starting from a ND? BEA doesn't give a clue.

However, if in any way established nose down, (descent), this would explain the extra time it took for her to reverse her nose transit to "UP".
It also would explain a lagging and exaggerated AoA at the initiation of the zoom. 7000fpm for 35 seconds is 3500 feet (+). Yet we are told that she had PF ND inputs which reduced the Vs to 700 fpm, and continued to 380.

Had she started to climb from 350, she would have flown to 385 and then coasted up to 390. This is not the case, and makes a good argument for her beginning this post a/p climb lower than we think.

I also appreciate your acknowledgement that mechanical issues may have been in play. A Speedbrake deployment is ripe for explaining the onset and chronic display of Right roll. A left Roll correction would drop the Outer (right) aileron, and complete a split surface drag that would be remarkable. If the spoiler was not retracted for any reason, the Starboard wing would continually want to horse the a/c down and right.

Kind regards, and deep respect.

jcjeant

But the a/p does 'give up' before the a/c is out of control or in an excessive or unusual attitude, surely. That is what it is programmed to do, and not wait until pitch or lateral control is as good as lost. It's a fair or reasonable assumption, though one could postulate a single upset that 'might' at one and the same time disconnect the a/p and fully upset the a/c...

Seems from the last BEA report that's not what they are thinking though...

Harry Mann

Hi. The a/p is required for flight into turbulence, and its limits are virtually identical to what is defined as "Upset". So, the a/p could easily have been bumping up against its mechanical limits for continued select. Technically, then, the PF was (may have been) in upset when he "I have the controls"....? LOC came with the STALL, and the initial STALLSTALL may have been quite valid, exceeding the AoA threshold for warning as the ship climbed (rotated) smartly at .81M. Comes the MASTER CAUTION, and the CAVALRY CHARGE, and the workload (and sensory load) get rather.....extreme?

cheers

HarryMan;
Yes, I think so. Each paragraph in your post has something important to say about the change, or rather "the shift", but your last paragraph is exceptionally important, the justification being economic.

The traditional controls (even the stick) are a concession to history, but in truth, because it is all digital, the thrust levers, (for example) could have been four push-buttons (for each detent) or sliding dimmer switches. The "cultural" collision has been between the necessary ultra-conservative, (as in extremely slow to change/alter familiar controls which we operate on an entirely sub-conscious level) and the entirely new developments in control (with a bow towards ergonomics) made possible by reliable, light-weight chips and wires. (I do not mean to downplay here the complexity and vision of the concepts which underlie the design).

The failure hasn't been in the concept and resulting design but in the lack of anticipation of the philosophical change in "world view" from the cockpit with regard to very specific technical tasks, right down to the practical "how do it know?" puzzlements of crews brand new to the airplane. Your comment regarding "being open" means (and meant) to me that if one didn't like what it was doing, one disconnected it and flew it like a DC9 or a B737. My 15-year experience reified that view completely.

One just simply didn't accept that this airplane, any airplane, couldn't be stalled and so flew it with the same respect and knowledge one had for the boundaries of controlled flight and certification limits as one always had with one's aircraft. It doesn't take much observation to see that that understanding has changed over the years.

In early years of "the shift" however, it wasn't "more of the same" in the sense that the shift from piston-to-jets, straight-wing to swept wing, mid-altitude to high altitude flight took beginning in the late 50's was still with a conventional cockpit with conventional controls. The accidents were due to slower acceleration (engine and therefore airplane rates - no big 'wash' over the wing from the props, - higher weights, higher altitudes where yaw dampers and Mach number meant something, an extremely clean profile, and the effects of buffet boundaries never encountered in piston flight.

Indeed, if one is entirely open it can be successfully done and to a very large extent, has, as the accident data has borne out. The other side of "the shift" is reading into the design and the aircraft, more complexity than is there which leads to second-guessing and out-guessing the solutions to the problems of flight, which, as gums consistently discusses so well apropos his fighter experience, still are new to transport aircraft. Despite the complexity underlying the relative simplicity of the cockpit, the airplane remains an airplane when one "looks through" the levels of automation. Despite minor disagreements, BOAC's and NoD's comments, as I have read them, reinforce this important notion. In this accident, I think that there is very rich learning for those well beyond and upstream of the cockpit.

Hi,

Well at today technology available a plane like a Airbus can be piloted with some tactil (touch) screens .. a keyboard and a mouse as bonus ...
All is available for that ....
It's already at work in some industries ......
And all this can be remote controlled if necessary ..
The ingenuity of humans and progress never stop ... :)
We go on the Moon ... after all .... :D

Ah, yes.

However, I think PJ2 is more concerned about the problem of "when it's working it's real fine but when it falls in a heap and dumps the lot in the pilot's lap ... what have we done to ensure that the average line pilot - and, in this case, the average pair of line F/Os - is up to the task on the day (or the dark and stormy night, as the case may be) " ?

We should all acknowledge the overall fine record of the Airbus approach to life and the general statistics of the safety record but, when I look at the postulated attitude presentation a couple of pages ago and consider that that looks not unlike an early jet A/H (think, say, a 733 with the FD selected OFF) - which, together with a handful of throttles, we could all use to pilot the aeroplane quite nicely .. I am left wondering just a little whether the Industry has been seduced by the siren of Gee-Whizzery and, perhaps, lost the basic pilotage competence plot .. at least just a bit ?

aircraft are aircraft. even drones are aircraft
 

TNX for nice words, PJ.

I only jumped in here because I am now a SLF and it's really hard to "ride" when I see things happening and wonder what in the hell the troop up front is doing, or is capable of doing. I just want to feel safe!

If we all wish to have the remote operator back in an air-conditioned room, with all kindsa displays and such, who "steers" the jet, then I will quit riding.

When I look at all the "protections" such as bank angle, AoA limits, auto-throttles that depend upon various flight phases, etc. etc. ad nauseum. I get scared. Don't get me wrong, as I used my autopilot a lot in the lites I flew. I used them to reduce workload, and not to accomplish the mission. But this 'bus implementation seems too much of a pinball machine or video game for 90% of the mission. And the philosophy is reflected in all the "laws" and "alt laws" and sub laws.

The plane we're discussing seems to be a very fine jet, with great aero performance and stability and...... It does not appear to have any terrible or unusual flight characteristics that a basic pilot could not handle. The big "BUT" for me is the plethora of "protections" and laws and sub-laws and on and on that do not seem necessary. I fully understand autopilot functions that ease the workload. So my big "BUT" is the extent to which those AP functions are integrated into the jet's flight control laws. And IMHO, they need not be so closely coupled.

Sorry to rant...

Ongoing certification process
 

syseng68k,

thank you for your response regarding "certification after initial" for computers and other parts. Will look it up.

Do you mean subsystems inside one given computer/unit, inside one PRIM or inside one ADR for example ?

Or could we have interaction between systems (one PRIM talking with one ADR), such interaction being along a multiplexing line shared by many other units ? How is this last one dealt with in "recurrent-next-version-testing" ?

I understand you might wish to distinguish between these two issues, although from the perspective of the "user", this still appears as a "bug" (and not as a feature :}). I mean "bug" in the sense that a computerized system acted in ways unexpected both by its user and its designer. It remains explainable and tracing the lines of code one would understand why it did that. But the main issue is that behaviour of the system is not expected by anyone.

As a native speaker told me : "I know it's not what you meant, but it's what you said." This about sums up a workable definition of a "bug" for me, both from the programmer's point of view, and the user's.

Back to the PFD illustration. Is there any evidence the altitude display had been removed as shown?

gums,

I do agree, the 320 and followers would have been much better aircrafts without such complexity.

FBW was needed to save weight and attract the clients, fine, were the protections their request too ... I don't think so.

Starting with the autotrim under manual flying ... who needs anything like it ?
To have to trim under manual flying has always been part of the pleasure and understanding of what it's all about piloting.
Raise your hand if you thought that an autotrim under manual flying was a necessity (Remember your time on the other types ...)

AF447 has been autotrimmed to the max up position under STALL WRN ... something is awfully wrong here !
At least, leave to the pilots that responsabillity if such was really their wish ...

- John - why not come over to the Safety forum and join my thread - the water is lovely and warm:)

Unfortunately I am not a pilot and this is my first post on this tragedy, but from my limited understanding of the trim function, it is to take the load of the control column or stick to reduce or maintain a balanced feel with no loads felt.

Obviously in the Airbus with the stick having no feedback on control surface loads, I therefore assume the trim is there to reduce hydro-mechanical /electro mechanical loads on the actuation systems during ascent, descent and level flight modes. If this is the case how would the pilot manual trim in alternate law?

What would be his indications to make the corrections? Why with the stick back would auto trim go to fully max with such a low horizontal speed (i.e. elevator control surface loading would have been at a minimum if the aircraft was at or below stall speed , does vertical speed have an influence here?)

May I rewind to thread #1? As we approach 900 posts on this thread (4), we are really no further forward, 'experts' having 'dissected' the computer logic, argued with each other over what 'latches', 'defaults', 'degrades' or 'votes' etc etc - and we are all ignoring the basic puzzle.

Why did they climb so steeply? I still remain suspicious of the limited CVR release from BEA. I cannot accept that ANY pilot, out of line training, would sit idly by while the other pitches up to a large angle and the altimeter (and IVSI?) scream skywards. Why is this part missing? Let me make it clear, I do not wish to hear 'the voices', but where is the crew inter-action?

So, either PNF saw this climb or he didn't. If he saw it, what was said? You just do not zoom up that level at that weight in the ITCZ, if anywhere.

Now to the second option, he didn't. Way back on thread #1 I asked whether the ADIRU in this failure situation would degrade to IRU or lose all, and I was assured that attitude and inertial info would 'remain'. Suppose it did not.

What do we have?

We are expected to accept a silence in the cockpit while this manoeuvre takes place (and indeed much of the to and fro on these threads ignores this) following

PNF "so, we’ve lost the speeds" then "alternate law […]" followed by

PF "I don’t have any more indications", and the PNF said "we have
no valid indications".

None of this fits with Mr Occam.

If we are looking at the former option, huge and worrying questions on the philosophy of operation of this aircraft in general and AF training arise.

If the second...........

Instead of all the pilots here proving how clever they are at deciphering the IF....THEN and WHILE....WENDs why do they not address the basic PILOTING illogicality of all this? After the first 2 stall warnings, none further during the climb. PF makes 'nose-down' inputs, the climb continues but levels out. NO sign up to now of any more stall or overspeed, indeed no sign of the extant stall recovery actions of stick back and TOGA - until a new stall warning. So why climb? I just do not understand. Is it to be believed that two adult, trained pilots would react this way?

It might be called "auto trim" but "trimming" seems to be only part of it's function. From descriptions here and in the reports it sounds more like a form of "power assisted steering". It sounds like when you call for a lot of up/down elevator it's the auto-trim that (eventually) delivers a large part of it?

With that in mind I'm unclear why the auto trim function is lost in direct law? Let me re-phrase that.. I can see why automatic control might have to disconnect but not why the pilot should be left with reduced maximium control throws and have to use manual trim to supliment them?

The available throw from the trim system seems to be very large? Under what conditions do you need so much up/down trim? Landing only?

or am I missing something?

But you can't infer from that information that the PNF was unaware of what was going on because he wasn't getting any feel through his sidestick. Perhaps he felt that the other pilot was doing what was necessary, perhaps he didn't feel confident enough to intervene (see Birgenair again), perhaps he got absorbed in the "PNF" role to the extent that he was more focused on the ECAM messages than his PFD or - and I know this will be controversial - perhaps he'd fallen asleep and was woken by the alarms. All of which are possible, but we don't know - we'll find out with the arrival of the report.

I disagree - saying that the system behaved as designed and that design is logical is categorically *not the same* as blaming the pilot. You're taking a technical aspect of the discussion and trying to make it emotional.

Also, confusion re: Law is (IMO) not the issue. At its most basic (and this is something I've been trying to get through to gums on as well), all you have to know about Law in a pressure situation like the one these guys were in is that you can't rely on hard protections once you're out of Normal Law - the very existence of the Alternate laws is to make sure that the aircraft handles much as it does in Normal Law, and we've had several posts from current FBW Airbus pilots stating that this is indeed the case.

As I said, I expect this aspect of the case will be causing a very thorough human factors investigation on the part of the BEA - if they didn't release it last month, I suspect it's because they're unsure of the significance of what (if anything) was said.

I think you'll find that it's been us techies trying to decipher the logic flow rather than the pilots "trying to look clever". And the fact is that occasionally pilots do illogical things. All this back-and-forth isn't really getting us anywhere and is simply giving those with an axe to grind an opportunity to hammer the square peg of this case into the round hole of their preconceptions.

(Also, you're definitely showing your age with the WHILE/WEND comment, as am I by acknowledging that I know what it means... :8 (I haven't written any Pascal since I finished my A-Levels, and it was pretty old hat even then!))

Well - kind of but not really, especially from the late 1960s onwards. The cockpits may have *appeared* conventional but were in fact masking a complex fully-hydraulic system with no direct connection to the flight surfaces in the traditional sense, as some early DC-10 pilots and the crew of JAL123 sadly learned the hard way.

I know you know this by the way, just putting it down in the record. :)

And the aforementioned "loss of hydraulics" accidents in the third generation jets.

BOAC:

To answer your pilotage question, Mr Occam suggests to me a scan breakdown (and PNF heads down in a display/ECAMS series of tasks) in the style of

artificial horizon/attitude indicator
+
altimeter/altitude strip

dropped out of the PF's scan in favor of something else (something to do with airspeed or secondary effects of that system having a hiccup).

Attention thus diverted, a small input in the stick over time became substantial THS deflection ... hence the 30 seconds of inexplicable nose up input, and beginnings of roll series.

This guess derived from a few years of testing two seat crews with a variety of malfunctions and seeing some focus (as a team) on the malfunciton, and others dividing tasks, one flying, one troubleshooting.

The CVR info might be helpful in understanding how close a guess this is to actual events.

@bearfoil: it does not appear that a/p is required to penetrate turbulence, though I think every AB pilot would prefer it. From what the AB pilots have shared in the various threads, one could (gasp) hand fly by using conventional scan pattern and gently setting and keeping an attitude (nose) and wings as level as possible as one rides out the bumps.

Auto-trim is necessary in order to implement a load factor demand pitch law. The aim is to get a constant path free stick behavior, i.e. a path independent of speed, thrust or configuration. I didn’t try it myself but it could well be that with a sidestick controller such a behavior is better and preferred compared to a more conventional “trim to speed” system. However, you need to add protections at both ends of the longitudinal flight envelope if you want the system certified for commercial operations, hence the high speed and high angle of attack protections.

Problems appear at less than Normal Law due to protections removed but then basic certification requirements don’t apply. You are left with stall warning only in ALT 2 law.

100% agreed.

There is something paradoxical with this new “space aged” flight control system. Certainly the airplane is easy to hand-fly in normal mode, perhaps a bit more “touchy” in alternate mode where default gains are used and again more sensitive in direct mode. Easiness has been used as a commercial argument to customers, suggesting savings in training. We, old pilots, having used “dinosaur” flight control systems regularly disconnected automation, even at altitude, when we felt we could do better manually, which was often the case. At the time, we were never really in need to “update” our skills in this respect and today the background experience is still there.
Now think about the current situation of young pilots. They are just given a taste of direct law in the sim, not necessarily at altitude, a few minutes once every 4 or 5 training session and the rest of their hand-flying life is Easy Law, follow-the-FD-it-is!!! Yet, they are supposed to have a decent level of flying skills when they are abruptly passed a less than optimal system. The paradox is that making the task easier erodes the necessary skills i.e. does not systematically result in enhanced safety.

Roll control was maintained which indicates attitude data OK.

Mr O.

Ideally, roll control being maintained would mean to me the PF remained wings level when that was the called for flight regime: maintain course and speed to get to next navigation point.

You are probably right, but the BEA reports roll excursions. One need not fault the attitude indicating system for that ... other explanations have been offered that do not point to a failure, for which various data to date have lacked one labeled "inertial reference/AI" failure.

A/P is "required" by SOP via Airbus, not in some mechanical requirement. Leaving the controls alone is not unwise in turbulence, where "maintaining" trumps "maneuvering" yes?

There is one other interface in the mix that gets little attention, that being auto v. mechanical?

The Sidestick would seem to be an attempt at "feel" retention. As such, perhaps jcjeant's touchscreen would be a more honest approach? The THS is powered by a jackscrew via hydraulic pressure, not the speediest method of response. Trim implies "relief", not control.

TRIM accomplishes a stability in pressure, independent of deflection. This is a valuable resource when "maneuvering", for it communicates the a/c demands and wishes to the flyer. Does the FCS have need of this "feel"?

Such a valuable resource to eliminate from the endeavor! As to certification, why would a THS be required to plant at max deflection and stay there whilst a recovery is attempted? And if not required for certification, the a/c must be recoverable with elevators only, I would think. So why is the HS even allowed such an excursion?

This thread is generally peopled by those who would grant the system a pass on criticism in the LOC/event arena. Yet the pilots are referred to as "Why in the World...?"

Either the PF knew not the position of the THS, or he disregarded it.

Again, the answer, for me anyway is to be found in the seconds leading to a/p disconnect, and those few that elapsed at the initial climb.

The PF completely ignored the TRIM WHEEL? He commanded a ridiculous climb at low energy? He held backstick seven miles down into the SEA?

Absolutely not. From the outset, BEA has been manipulating public opinion re: this accident in the worst of ways, impugning the pilots, to include those who were open to continued UAS events. Does anyone doubt the motive behind the "Note"? Airbus got, and then sent, the message, n'est-ce pas?

bear, It is impossible to slander without abusing the TRUTH.

bear, in re words and terms, and a little too much "all or nothing" in your reply:

No. You make an assumption there, that not having A/P available means that controls are left alone. I respectfully disagree, having flown in turbulence more than once, with and without an autopilot function (though not on an Airbus, of course).

Not as described in a myriad of posts by pilots who fly Airbus airliners, no. You and I may have gleaned different messages from same posts. Perhaps I am the one misreading. No idea. Haven't tried to fly a plane by touch screen.
It seems to work pretty well, doesn't it? I don't know if speed of response is the critical metric, given that rate damping and control damping are features common to various FBW aircraft, as well as some AFCS and EFCS suites in non-FBW aircraft.

I also recall that the elevator is generally involved in THS lift adjustment under all laws but direct. The way I read the block diagram, when you use trim wheels, the elevators don't do much, so you are moving the THS, but I may be misreading that block diagram. That would explain why those who have used it have to be very careful with trim wheel control of pitch, as the fine pitch trimming, or fine pitch control, via elevator adjustment isn't to hand in that case.

If I have misread the block diagram, my apologies.

Beyond that, any semantic argument about what trim should mean isn't as important as what you learn in type training, and follow on training, about how your flight control system and auto pilot functions work, in full up modes and in degraded modes.

The first fleet helicopter I flew had a different trim system, and different AFCS, than the second fleet helicopter I flew some years later. Just because the trim systems didn't work identically doesn't mean that I could not trim the aircraft, didn't understand how to, or was somehow at a loss.

You learn to fly your aircraft.
It's what good pilots do.
It's what professional pilots do.
If for one reason or another there is a systemic obstacle to such systems familiarity, that must be addressed.

EDIT: I may be dating myself. AFCS "automatic flight control system" and EFCS "electronic flight control system" (now DFCS??) which abbreviations may no longer be in general usage.

Lonewolf 50

This thread is impossibly iterative, and requires, imo, a lot of leeway in particular opinions. For example, SmilinEd said ages ago that a/p in turbulence may need a look see. It may not keep up with its own mission, relative to trend, and rapidity of surface deflections required, which may not be appropriate. Airbus strongly recommends using the a/p at all times, and each operator generally demands the same of each flight crew.

Is there an "EASY!" switch on otto? A mode that will tolerate serious bumps and puckering ride in patience, while anticipating some relief soon?

AF447 was in the bump city, by BEA portrayal, via Captain duBois. Yet the crew remained in a/p, as expected, and when it quit, there was the mundane handover, "I have the controls". No big.

The THS' jackscrew works fine, it is appropriate for a large airliner that needs gentle and deliberate deflections. That it took sixty seconds to travel from three degrees to thirteen seems appropriate for its size, that of a large dancefloor used to manipulate 150 tons of mass.

Without assigning any rating to each post, relative to experience and knowledge, my goal is to be critical of the failures here in man and machine, and learning as much as possible in the process. Please continue to correct where necessary, :ok:

But, IMO, direct law would have done just fine whenever AP is OFF.
Anyone here complaining about flying the 320 in direct law ?


From my personal experience, I just don't know what my partner is doing with his sidestick. At best, and it's not necessarily better, I'm guessing ...

When the captain came back, he probably took the middle jumpseat, from where, you hardly see any of the sidesticks ... How can he evaluate the flight control inputs ?

And forget about falling asleep at that time. Did the captain fall asleep as well after entering the cockpit ? Is it why the BEA could not publish any comment from him ...

Initial pitch-up
 

bearfoil, BOAC, and others,
At risk of unnecessary repetition, the BEA Interim Report #2 (Page 48) shows that, with a sudden drop in the perceived dynamic pressure (blocked pitots) the ADR will infer a drop of altitude of the order of 300ft. So, while maintaining FL350, the altimeters might have dropped suddenly to indicate 34700ft erroneously. It's conceivable that this might have been the reason for the PF's initial pitch-up command.

In their most recent Update, the BEA says that ASI1 dropped from 275kt to 60kt, but I have to admit that at the moment I don't know which altimeter reading that would have affected. Perhaps one of our ADR students will shed light?

ASI strip on PFDs
 

PJ2,
Thanks for the PFD and centre-pedestal pictures yesterday. At what stage would you say the ASI strips on each PFD might have ceased to indicate the current IAS/CAS calculated by the ADRs, and what would cause that? Must admit to being confused about this.

Are you hinting that its disappearance on PFD2 may have provoked the PF's remark at 02:12:02:
"I don't have any more indications" ?

We have seen a number of threads speculating on "how to stall" an AB 330.
Does anyone have access to a suitable simulator to see if or how the Captain might have recovered the aircraft, when he arrived on the flight deck ?
(AB are said not to have any data about a full stall - or it is not available.) A few attempts with our own or somebodies "Made-up" data might show - something instructive, even if it needed several attempts.
If there is some success whilst Pitot and Static are used, then try again, this time without. What is there to lose - for us ?
A couple of 747s have glided successfully ( if not intentionally).
Wasn't Cully's an AB...

Chris Scott, would AS1 be LHS? Pitot #1 is directly out the Captain's glass, and above Pitot #3? Straightforward, but I could not say for sure.

bearfoil,
Yes, that's my understanding. But I'm not sure that ADR1 displays both CAS and altitude on PFD1 (the L/H PFD). Now, where was that schematic that someone kindly posted an eon back? :{

Hi bear,
The more important questions we are left with are:
- Was a stall recovery really attempted? If, yes, when did it take place?
So far, I really can't say anything about it as we'll need the full cockpit conversations and many other data in order to settle this matter.

Same remark about the PNF "late" acknowledgement of "speed lost, Alternate law". Was it ever acknowledged by the PF?
What the PNF was trying to say to the PF then? Maybe his message was: "hey! no speed, alternate, no protections... what are you doing? we are climbing!"

Here, the question of each F/O aircraft experience seems critical to me. If the PF, like I think was the most senior with five times A330 more hours than the junior one, the PNF could have no choice left but to call for the Captain in support rather than taking-over. This may explain his early emergency calls.

All we can suspect, so far, is that the PF was attempting to do something as we have those stick imputs recorded. But what exactly was he really attempting to do? For me, it looks like he was trying to fly alpha-max as, at each STALL alarm, he reacted the same way by applying back stick imputs. It is called tunnel vision, sticking with the wrong choice by thinking that it is the good one.
We'll see.

I wonder why you call it tunnel vision instead of a conditioned response to procedural training, pattern mapping, or learned behavior.

PJ2 has time and again pointed out that a malfunction need not be treated as an emergency, nor turned into one, and I agree with that with the following caveat: once stall warning horn goes off, perhaps the crew went into emergency mode rather than malfunction mode. What was the last training session (that this crew participated in) involving stall warning horns dedicated to?

Recency and proficiency are training factors that must be considered.

(Once again, the pitch and power chorus will ask
'where was that conditioned response when warranted?'
in a lyrical, multipart harmony.)

takata:

When's the last time you taught someone how to do something?

How did you do it?

With over 800 posts even here you're excused....
The answers, already discussed earlier, are
a) no, there is no "suitable" simulator, since there are not enough aerodynamic data in the "full stall" domain to program a simulator accurately. Simulators are programmed for this domain by extrapolation, and "best guesses". And yes, it IS being looked at by work groups, etc. ;
b) we have nowhere near enough info about what happened in the AF447 cockpit to be able to write a "scenario" to try out what could have been done, even if we had that "suitable" simulator.

Hi Lonewolf,
I respectfully disagree with such statement.
So far, there is no such "conditioned response" measured behavior, including several other AF crews, as those many previous cases won't show any pattern of similar behaviors.
The more I can say, as there is not such a pattern during similar events, is that a specific training was lacking in most recorded case.

Chris;
This the one?

http://www.smugmug.com/photos/i-Sp8P...-Sp8P439-L.jpg


The photographs of the PFD without speed and altitude information have caused confusion for some - please accept my apologies.

In the post I did indicate that the altitude information would have remained, that the THR LK wouldn't have been displayed and that the FPV would not have been available, that there would have been a red "FD" flag and it was just the speed information that was missing, (removed if there is there is no data to display). I wanted to convey a sense of the display rather than portray it exactly as it was which of course isn't possible until we have more information.

The image below of the PFD is perhaps a more realistic representation of what the PFD may have looked like at the start of the climb. I caution everyone that this image is a composite, manipulated, Photoshopped picture and is just a guess and NOT related to anything other than my imagination. It is intended only to represent what the PFD may have looked like given what we know from the BEA Update.

http://www.smugmug.com/photos/i-QxQT...-QxQTz3m-L.jpg



Lonewolf_50 - yes, agree...My view has always been that the UAS event was not an emergency but it slowly turned into one the moment the pitch-up began and of course a stall is a full-blown emergency requiring an immediate response.

Notwithstanding notions that the aircraft was pitched down and the "correction" was to pull back on the stick, (doubtful I think), pitching-up and leaving "stable" flight meant that the last known-and-established variables, "pitch-and-power", were themselves intentionally varied, leaving no way back to stable, level flight, not, at least, without immediately setting pitch and power to the QRH settings and waiting (a very long time) for the aircraft to re-stabilize.

Others have said, and I agree, that even at the apogee, a full nose-down-stick-held-to-the-stops-power-off response, perhaps even without rolling the THS forward to something around zero degrees, would likely have led to recovery if not outright avoidance of the stall, (someone else said the aircraft was still at about 215kts and not stalled at the apogee).

Total red herring question probably, from a Concorde AFCS ancient.

When the air data part of an ADIRU goes 'belly-up' (in this case because of UAS) does that mean that the possibly still valid data such as altitude and vertical speed (static pressure data only) are also thrown out with the bathwater, or are there separate 'flags' (F/Ws) for separate data such as IAS, Mach, TAT, Alt and VS ?

IIRC, on Concorde all we (i.e., the AFCS) got from the ADCs was an ADC (1 or 2) failure warning. Period.
The AP and/or AT would drop out from internal command/monitor discrepancies between the ADC data, and in most cases also on an ADC F/W.
Since the INS was a totally separate system, it didn't really enter into the air data "discussion".

For clarity I should maybe add, that, for various (mostly irrelevant) reasons, between Concorde (the first FBW airliner....) and A320, the separate ADS (air data system) and inertial reference system (IRS) ended up inside the same system/box, now better known as the ADIRU.

takata

howdy sir. I think the CVR reports thus: (2:10:16?)

PF: "So, the speeds are lost."

PNF: "Alternate Law"

So, No mystery twixt the two at this point? If "simultaneous" mutual acknowledgment of the problem, a strong case exists for this being the first 'arrival' of Alternate Law (subject to a 1-2 second P(N)F recognition?)

If this voice is one only pilot, still, the recognition is established as well after autopilot drop.